It used to be easy.
A pressure transmitter gave you pressure signals as an analogue input into the DCS. What the DCS does with that data has nothing to do with the TX. Any output from the DCS could be in the form of a Digital ootput to some other device or system or maybe just creates a software command which shows up on the HMI as an alarm.
HH alarms tend to be generated from separate devices to the transmitter, especially if they are actually wired to the ESD panel.
These used to be switches, so a Digital input into the ESd or DCS.
But now more often, you find that it's actually a transmitter with a built in processor which outputs a digital signal DI into the panel.
An analogue output is a signal which varies between some valvues and is usually used to control something else (valve position e.g.)
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.